Speaker
Description
We investigate a sub-Chandrasekhar mass double detonation pathway for Type Ia supernovae arising from single degenerate helium accreting carbon-oxygen white dwarfs. Using one-dimension recurrent nova evolution code we evolve a 0.7 solar mass white dwarf through steady accretion at 10^-8 solar mass per year until it reaches 1.1 solar mass, yielding realistic, time evolved helium rich profiles. These profiles are mapped into FLASH simulations, incorporating nuclear burning for helium and carbon-oxygen detonation, in multi-dimensional hydrodynamic runs. A localized, modest temperature perturbation near the base of the helium shell robustly triggers an outward helium-shell detonation. The ensuing inward propagating shock converges in the carbon-oxygen core, igniting a secondary detonation that unbinds the star. We obtain a Ni56 yield of ~0.64 solar mass, an intermediate-mass element (Si-Ca) mass of ~0.41 solar mass, and maximum ejecta velocities approaching 22,000 km/s, values consistent with normal Type Ia supernovae. Our results demonstrate that recurrent helium accretors, typically quiescent over long timescales, can evolve under subtle, "quiet" conditions to trigger robust double detonations, supporting their role as viable progenitors of sub-Chandrasekhar mass Type Ia supernovae.
| Career stage | Early-career researcher (within 5 years of PhD) |
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